58 ME. A. HARKER OK THE GEOLOGICAL [Feb. 1906, 



under my eye on two occasions, once in the presence of Dr. Peach ; 

 and Mr. D. Tait, who visited the place to collect for the Geological 

 Survey, has also furnished me with some notes to supplement 

 my own. 



The base of the fresh columnar pitchstone, forming the roof of 

 the recess or gallery, has, as usual, an inward dip, although the 

 general inclination of the great sheet is, in this part of the Sgiirr, 

 in the opposite direction. The hase of the pale decomposed band 

 (X in fig. 5, p. 57) has a similar dip, and the thickness of the hand 

 is here about 7 feet. As elsewhere, it contains, besides the blocks 

 of unaltered pitchstone and felsite, some pieces of basalt, which 

 become more abundant in the lowest part. In addition we find, 

 what are not seen elsewhere, fragments of Torridon Sandstone and 

 little pieces of fossil wood. In the lower part of the pale decom- 

 posed pitchstone, but distinctly enclosed in it, occurs the main 

 mass of wood (W) which has furnished the specimens of Pinites 

 eiggensis. There can be no doubt that this (as well as the Torri- . 

 donian fragments) has been taken up from the underlying breccia 

 presently to be described. Most of the wood, both in the main 

 mass and in the scattered pieces, is completely silicified, of a 

 lustrous hlack, and often shot through with slender threads of 

 white calcite ; but there is some which is not silicified, being 

 more or less carbonized, with a similar black lustrous aspect. 

 Mr. Tait's account is as follows : — 



' Here a log of fossil wood lies embedded, with its length parallel with the 

 length of the Sgiirr. The piece is about 5 feet long, as it now remains. 

 [I subsequently saw about 8 feet exposed. — A. H^\ Probably the heavier end 

 of the log lies towards the east, but this could not be definitely ascertained. 

 The log is about 8 inches in vertical height, and somewhat more in horizontal 

 breadth : this gives it a flattened oval outline in transverse section. It is 

 cracked and fissured in many directions, and pieces evidently belonging to this 

 trunk are completely separated from it. That these pieces do belong to 



this trunk is seen by their similarity of texture and their orientation 



Numerous fragments of smaller branches occur at this level. They are often 

 flattened into ribbon-shaped pieces, that lie flat on the bedding-planes. At 

 places 15 to 20 yards apart the matrix in which the wood is embedded is quite 

 different. In this woody layer, small angular stones are embedded. These 

 stones increase in number and size downwards, and so form the underlying 

 breccia exposed at the outer edge of the platform.' 



The last sentence would imply a passage from the pale band of 

 decomposed pitchstone (X) to the underlying breccia or agglome- 

 rate (Z). Dr. Peach and I satisfied ourselves that there is a clear 

 separation between them, although the pieces of extraneous rocks in 

 the former naturally become more numerous at its junction with 

 the deposit which supplied them. This deposit (Z) is of a very 

 variable character. It consists chiefly of fragments of various 

 sizes, with a smaller proportion of matrix, which is not always of 

 the same nature. Sandy or basaltic (perhaps ashy) material may 

 predominate, and there may or may not be sufficient calcareous 

 and ferruginous matter to make a binding cement. The fragments 

 are of red sandstone and other Torridonian rocks and of "basalt, 



